<math display='block'> <mmlrow> <mmlsub> <mmli>A</mi> <mmlrow> <mmli>A</mi><mmli>D</mi> </mrow> </msub> <mmlo stretchy='false'>(</mo><mmlsub> <mmli>V</mi> <mmlrow> <mmli>A</mi><mmli>D</mi> </mrow> </msub> <mmlo>&#x2212;</mo><mmlsub> <mmli>V</mi> <mmlrow> <mmli>t</mi><mmli>A</mi><mmli>D</mi> </mrow> </msub> <mmlo stretchy='false'>)</mo><mmlo>=</mo><mmlsub> <mmli>A</mi> <mmlrow> <mmli>E</mi><mmli>F</mi> </mrow> </msub> <mmlo stretchy='false'>(</mo><mmlsub> <mmli>V</mi> <mmlrow> <mmli>E</mi><mmli>F</mi> </mrow> </msub> <mmlo>&#x2212;</mo><mmlsub> <mmli>V</mi> <mmlrow> <mmli>t</mi><mmli>E</mi><mmli>F</mi> </mrow> </msub> <mmlo stretchy='false'>)</mo><mmlo>+</mo><mmlfrac> <mmlrow> <mmli>d</mi><mmli>V</mi><mmli>i</mi> </mrow> <mmlrow> <mmli>d</mi><mmli>t</mi> </mrow> </mfrac> </mrow> </math>